Gram-negative and Gram-positive bacteria colonize surfaces in health care settings, on indwelling medical devices, and even on live tissue, leading to infections that are often treated with antibiotic therapy. However, two major factors complicate the effectiveness of antibiotic treatments, namely (i) the rising number of antibiotic-resistant bacteria, and (ii) the formation of biofilms. These complications lead to increased patient morbidity, increased costs of treatment, and higher rates of hospitalization.
Antibiotic resistance is the inevitable evolutionary survival mechanism of bacteria which is aggravated by the over-use of antibiotics in the medical and farming industries. Bacterial biofilms are structured, surface-associated microbial communities, protected by a self-produced matrix of extracellular polymeric substances, and are the most common mode of bacterial growth. Formation of biofilms complicates the treatment of infections because bacteria in biofilm mode are generally very persistent, requiring considerably higher doses of antibiotics for treatment compared to planktonic bacteria. High antibiotic doses disturb the body's microbiome, putting the patient's health at risk, as well as increasing the potential for development of antibiotic-resistant strains.
In view of the reduced effectiveness of current therapies and a declining repertoire of clinically useful drugs, there is a need to be provided with molecules endowed with antimicrobial and/or anti-biofilm properties.